Fluid compressor



June 22, 1937. P. 1.. CRITTENDEN FLUID COMPRES SOR Filed Jan. 51, 1935 3 Sheets-Sheet l C o o o 0 EH1 o s fi INVENTOR PHlLlF LORI [TENDER ATTORNEY June 22, 1937. CRITTEND'EN 2,084,670

FLUID COMPRESSOR Filed Jan. 51, 1935 3 Sheets-Sheet 2 flfk lh [I ELL I 8 ATTORNEY Patented June 22, 1937 PATENT OFFICE FLUID COMPRESSOR Philip L. Crittenden, Edgewood, Pa., assignor to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania 4 Claims.

riThis invention relates to a fluid compressor and more particularly to an improved air compressor of the liquid cooled type having unloading means associated with the suction valves for 6 the compressor cylinders.

:Liquidcooled air compressors are in use at the present time, but these are not entirely satis- A'further object of the invention, is to provide a fcompress'or incorporating unloading means comprising means to maintain the suction valve open. the suctionvalve and unloading means heing'con struct ed so that it can be readily removed and replaced};

"iAfurtherbbjeot of the invention is to provide an improved, air compressor. v 4 the'robjectsof the invention and features of 39 n'ovelty will-be apparent from the following description taken in connection with the accompanying drawings; in which ffFigure '1 is a sideelevational view of one embodiment of the improved compressor provided b'y'my invention;

Figure Zis an end elevational view of the compre'ssor shown in Figure 1;

1 .l?i'gure 1351s a sectional view taken substantially 'along' the line 3--3 of Figure 2 with portions shown in elevation; I

" Figure lis'a sectional View taken substantially along the line 44 of Figure 3; j

j Figure 5 is a! sectional view takensubstantially along theiline 5 '5 ofFigure 3; and Figurefi is a fragmentary sectional view taken substantiallyalong the line 66 of Figure 5. v Referring now to the drawings, the compressor therein illustrated has a cylinder casting in- 50 dic ated, generally by the reference character l0 and which may be of any suitable construction. As illustra'te'd, the cylinder casting I0 has the crankcaseformed integral therewith, and, in addition; has the cylinders ll formed therein, in 55 reciprocable the pistons l2 which are o'ryas in these compressors; it is not possible- 1 ApplicationJa-nuary 31, 1935, Serial No. 4,263

mounted on connecting rods 13 having their lower ends secured to the throws M of the crank shaft I5 which is rotatably supported on bearings secured in the cylinder body H]. A jacket I8 is formed around the cylinders H so as to 5 provide a chamber [9 surrounding the cylinders and adapted to hold a quantity of a suitable cooling medium such as water.

As is best shown in Figs. 3 and 4 of the drawings, the cylinders II are each provided with a plurality of axially extending ribs or fins 20 which project into the chamber l9 which is adapted'tohold the cooling medium. Because of the large surface area of the fins 20 there is a large heat radiated surface for each of the cylinders II, and the heat which is generated in the cylinders as a result of the compression of the fluid in these cylinders may be carried through the cylinder wall and transferred to the cooling medium in the chamber l9. 0

In the preferred construction the fins which projectfrom the cylinders ll into the chamber l9 extend axially of the cylinders substantially the entire length of the cylinders and project from the cylinders in planes which are substantially perpendicular to the plane in which the cylinders are disposed. In addition, the fins on each cylinder which are adjacent a plane perpendicular to the plane in which the cylinders are arranged and which extends through the center of the cylinder, project from the cylinder a smaller distance than the fins which are remotefrom this plane. This arrangement of the fins permits the cylinders II to be placed somewhat closer together than is possible with radially extending fins and at the same time insures that the cylinders will be adequately and uniformly cooled throughout their entire circumference as the heat dissipating capacity of the individual fins is increased in those portions of the cylinders in which the circumferential spacing of the fins is increased.

The compressor has a detachable cylinder head secured over the tops of the cylinders I I by means of the bolts 26. The cylinder head 25 has chambers therein extending through the cylinder head, and including a chamber indicated at 30, and adapted to contain the exhaust valve assembly indicated generally by the reference character 3|. The chambers each extend over a. portion of one of the cylinders II, as is best shown in Figure 5 of the drawings. Similar chambers 30 are provided for each of the two cylinders in the compressor shown in the drawings, and these communicate with a manifold formed in the cylinder head and indicated at 34. A discharge pipe 35 leads from the manifold 34 to carry away the fluid compressed by the compressor.

Inlet chambers 40 adapted to receive the inlet valve assemblies indicated generally by the reference character M, are also formed in the cylinder head 25 and each of these chambers extends over a portion of one of the cylinders II and the chambers communicate with the manifold 44 which is supplied with air from the inlet pipe 45. The head 25 is provided with a jacket 48 extending around the chambers 39 and 40 and the manifolds 34 and 44 and forming a chamber around these portions adapted to contain a quantity of cooling liquid. A pipe 49 is connected to the head 25 to carry away the fluid which passes through the chamber in the cylinder head.

The construction of the valves employed in the compressor provided by my invention is best shown in Figure 6 of the drawings, where it will be seen that the exhaust valve assembly 3| comprises a seat element 69 adapted to rest upon a shoulder SI formed in the cylinder head. The seat element 90 contains a plurality of ports 62 arranged in two annular series and adapted to be closed by the annular valve members 63 and 64 which are normally held in the closed position by means of springs 65-which are seated in a spring retainer cage 68. The spring retainer cage 68 and the valve seat 60 are held in place by means of a spider or cage indicated generally by the reference character I0, and which is securely held by means of a clamp or plate II which is bolted to the top of the cylinder head, and which has the adjusting screw I2 threaded therein and engaging the spider I9 to press it downwardly to hold the members 69 and 6B in place. When it is desired to remove the exhaust valve assembly for servicing or for other purposes it is necessary only to remove the clamp or plate II. This permits the exhaust valve assembly to be lifted out of the chamber 30.

The inlet valve assembly M is generally similar in construction to the exhaust valve assembly 3!, and as shown in Figure 6 of the drawings, it is arranged in the chamber 40 in the cylinder head and comprises a spring retaining cage 80 seating on an annular shoulder 8| adjacent the lower end of the chamber 40. 'A valve seat 83 is positioned above the cage 80 and has a plurality of passages 84 extending therethrough and arranged in two annular series. A pair of annular valve members 85 and 86 are positioned between the spring retaining cage 80 and thevalve seat 93 and are normally urged against the seat 83 so as to close the passages 84 by the springs ill which are held by the retaining cage 80.

The spring retaining cage 80 and the valve seat 93 are held in position by means of the spider or framework indicated generally by the reference character 99 and comprising an annular peripheral portion 95 and a plurality of diverging arms 92 which extend upwardly and inwardly from the annular peripheral portion 9| and merge into a central portion in which is formed a. cylinder 95 which is open at the lower end. A piston 96 is positioned in the cylinder 95 and is reciprocable therein and has secured to the lower face thereof a plurality of fingers 95 and 99 which extend into the valve ports 84 so that when the piston 96 is moved downwardly the fingers 98 and 99 engage the valve members 85 and 86 to press them'away from their seats in the valve seat 83 and thereby hold the inlet valve open. A spring I is positioned between the piston 96 and the valve seat 83 and normally urges the piston 96 upwardly so that the fingers 93 and 99 do not engage the valve members 85 and 86. v

The cylinder 95 has a wall I extending across the upper end thereof and this wall has a passage I06 extending therethrough. An annular gasket I0'I is secured in a groove in the upper face of the wall I 05 and is engaged by the clamp or cover plate I I0 which is secured on the top of the cylinder head. The gasket I0! is preferably constructed of resilient material, such as rubber, so that it will effectively seal the area around the top of the cylinder 95 even though the distance between the upper end of the cylinder 95 and the lower face of the clamp or cover plate H0 varies somewhat in different installations. The clamp or cover plate H0 has an adjusting screw H2 threaded therein and engaging the central portion of the wall I05 so as to press the cage 90 downwardly to hold the spring retaining cage 80 and the valve seat 83 securely in place.

In addition the plate H0 has a passage H5 formed therein and communicating with the chamber defined by the annular gasket I 01 and with a similar passage I I6 formed in the cylinder head 25. If desired, a bushing II'I may be fitted around the passage and extend across the joint between the cover plate I I 0 and the cylinder head 25 to prevent the escape of the fluid through the joint between these members. I

When fluid under pressure from any suitable source is supplied to the passage H6 it flows through this passage to the passage I I5 and therefrom to the passage I06 through the wall I05 to the upper end of the cylinder 95 and exerts a. pressure on the piston 96 forcing the piston downwardly against the spring I00 so that the fingers 99 and 99 press against the valve members 85 and 86 to hold them in the open or unloading position. When the pressure of the fluid in the cylinder 95 is released the spring I00 returns the piston 96 to its upper position and allows the inlet valve to again be closed by the springs 81.

When it is desired to remove the inlet valve assemblies for servicing or for other purposes it is necessary only to remove the plate H0 which is accomplished very readily. The inlet valve as semblies can then be lifted out through the opening uncovered by the plate H0.

From the foregoing it will be seen that the improved compressor provided by my invention hasmeans to insure proper cooling. of the cylinder walls.

It will also be seen that the improved compressor provided by my invention has an inlet valve incorporating unloading means and that this valve is constructed so that it can be readily removed and replaced for service or for other purposes.

While one embodiment of the improved compressor provided by my invention has been illustrated and described in detail, it should be understood that the invention is not limited to these details of construction but that numerous changes and modifications may be made without departing from the scope of the following claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a fluid compressor, in combination, a body comprising a unitary casting having a cylinder portion having a bore extending therethrough and adapted to receive a piston, a jacket surrounding a portion of the cylinder portion and forming a chamber adapted to contain a cooling liquid, fins formed integral with said cylinder portion and extending into said chamber, the fins extending axially of the cylinder portion and projecting from the cylinder portion in substantially parallel planes.

2. In a fluid compressor, in combination, a body comprising a unitary casting having a cylinder portion having a bore extending therethrough and adapted to receive a piston, a jacket surrounding a portion of the cylinder portion and forming a chamber adapted to contain a cooling liquid, fins formed integral with said cylinder portion and extending into said chamber, the fins extending axially of the cylinder portion and projecting from the cylinder portion in substantially parallel planes, the fins on the said cylinder portion adjacent a plane of the center of the cylinder projecting from the cylinder portion a distance less than the fins remote from said plane.

3. In a fluid compressor, in combination, a body comprising a unitary casting having a plurality of cylinder portions each having a bore therein and adapted to receive a piston, a jacket surrounding a portion of the said cylinder portions and forming a chamber adapted to contain a cooling liquid, fins formed on said cylinder portions and extending into said chamber, the fins extending axially of the cylinder portions and projecting therefrom in substantially parallel planes.

4. In a fluid compressor, in combination, a body comprising a unitary casting having a plurality of cylinder portions each having a bore therein and adapted to receive a piston, a jacket surrounding a. portion of the said cylinder portions and forming a chamber adapted to contain a cooling liquid, fins formed on said cylinder portions and extending into said chamber, the fins extending axially of the cylinder portions and projecting therefrom in substantially parallel planes, the fins on each of said cylinder portions adjacent a plane perpendicular to the plane in which the cylinder portions are disposed and extending through the center line of the said cylinder bore projecting from the cylinder portion a distance less than the fins remote from said plane.

PHILIP L. CRI'ITENDEN. 

